95 research outputs found

    The Strain-Encoded Relationship between PrPSc Replication, Stability and Processing in Neurons is Predictive of the Incubation Period of Disease

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    Prion strains are characterized by differences in the outcome of disease, most notably incubation period and neuropathological features. While it is established that the disease specific isoform of the prion protein, PrPSc, is an essential component of the infectious agent, the strain-specific relationship between PrPSc properties and the biological features of the resulting disease is not clear. To investigate this relationship, we examined the amplification efficiency and conformational stability of PrPSc from eight hamster-adapted prion strains and compared it to the resulting incubation period of disease and processing of PrPSc in neurons and glia. We found that short incubation period strains were characterized by more efficient PrPSc amplification and higher PrPSc conformational stabilities compared to long incubation period strains. In the CNS, the short incubation period strains were characterized by the accumulation of N-terminally truncated PrPSc in the soma of neurons, astrocytes and microglia in contrast to long incubation period strains where PrPSc did not accumulate to detectable levels in the soma of neurons but was detected in glia similar to short incubation period strains. These results are inconsistent with the hypothesis that a decrease in conformational stability results in a corresponding increase in replication efficiency and suggest that glia mediated neurodegeneration results in longer survival times compared to direct replication of PrPSc in neurons

    The globus pallidus receives a projection from the parafascicular nucleus in the rat

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    Study of the afferents of the rat globus pallidus (GP) with Fluoro-gold, a retrograde tracer, revealed retrogradely labeled neurons in the ipsilateral parafascicular nucleus of the thalamus (PF), a previously undescribed afferent of the rat GP. We used the anterograde tracer, Phaseolus vulgaris-leucoagglutinin (PHA-L), to confirm and extend our findings. After injections of PHA-L in the PF, labeled fibers with varicosities and terminal specializations were observed in the ipsilateral GP. The topographical organization of the projection is such that lateral and ventral PF neurons project preferentially to respective parts of the GP, and medial PF neurons project primarily to the ventral GP. There were very few labeled fibers seen in the dorsal or medial GP. The presently described projection from the PF to the GP provides an additional route for the PF to influence basal ganglia circuitry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29231/1/0000286.pd

    Evidence for a projection from the globus pallidus to the entopeduncular nucleus in the rat

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    Iontophoretic injections of the fluorescent retrograde tract tracer, Fluoro-gold, into the entopeduncular nucleus of the rat (homologous to the internal segment of the primate globus pallidus) resulted in a substantial number of retrogradely labeled neurons in the ipsilateral globus pallidus (homologous to the external segment of the primate globus pallidus). In experiments confirming this projection, iontophoretic injections of the anterograde tract tracer, Phaseolus vulgaris-leucoagglutinin, in the globus pallidus resulted in dense fiber and terminal labeling in the ipsilateral entopeduncular nucleus. This projection is topographically organized in rostral-caudal, medial-lateral and dorsal-ventral orientations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29229/1/0000284.pd

    6-Hydroxydopamine lesions of the nigrostriatal pathway alter the expression of glutamate decarboxylase messenger RNA in rat globus pallidus projection neurons

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    In situ hybridization was used to study the effect of 6-hydroxydopamine-induced damage to the midbrain dopaminergic neurons on the level of glutamate decarboxylase mRNA in globus pallidus neurons in the rat. Some animals received an injection of Fluoro-gold in the entopeduncular nucleus or the substantia nigra prior to the 6-hydroxydopamine lesion in order to identify glutamic acid decarboxylase mRNA levels in pallidal neurons that project to one of these targets. Analysis was carried out on a sample of all pallidal neurons as well as neurons that were identified as projection neurons in control and lesioned groups.The loss of the dopamine-containing neurons in the substantia nigra resulted in significant increases in the percentage of globus pallidus neurons that expressed glutamate decarboxylase mRNA and in the amount of glutamate decarboxylase mRNA per globus pallidus neuron. These increases were noted in a sample of all pallidal neurons, as well as pallidal neurons that were identified as projecting to either the entopeduncular nucleus or the substantia nigra. In control animals, glutamate decarboxylase mRNA was clearly identified in globus pallidus neurons projecting to the entopeduncular nucleus, indicating that this recently reported projection is at least partially GABAergic.The results of this study indicate that substantia nigra dopaminergic neurons regulate globus pallidus neurons in the rat, and that removal of the dopaminergic input to the corpus striatum results in a significant increase in the amount of glutamate decarboxylase mRNA in pallidal neurons. The decreased firing rate of pallidal neurons that is seen following the loss of dopamine input appears to be accompanied by an increase in the level of glutamate decarboxylase mRNA in these neurons.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29707/1/0000039.pd

    Transverse Plane Tendon and Median Nerve Motion in the Carpal Tunnel: Ultrasound Comparison of Carpal Tunnel Syndrome Patients and Healthy Volunteers

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    The median nerve and flexor tendons are known to translate transversely in the carpal tunnel. The purpose of this study was to investigate these motions in differential finger motion using ultrasound, and to compare them in healthy people and carpal tunnel syndrome patients.Transverse ultrasounds clips were taken during fist, index finger, middle finger and thumb flexion in 29 healthy normal subjects and 29 CTS patients. Displacement in palmar-dorsal and radial-ulnar direction was calculated using Analyze software. Additionally, the distance between the median nerve and the tendons was calculated.We found a changed motion pattern of the median nerve in middle finger, index finger and thumb motion between normal subjects and CTS patients (p<0.05). Also, we found a changed motion direction in CTS patients of the FDS III tendon in fist and middle finger motion, and of the FDS II and flexor pollicis longus tendon in index finger and thumb motion, respectively (p<0.05). The distance between the median nerve and the FDS II or FPL tendon is significantly greater in patients than in healthy volunteers for index finger and thumb motion, respectively (p<0.05).Our results suggest a changed motion pattern of the median nerve and several tendons in carpal tunnel syndrome patients compared to normal subjects. Such motion patterns may be useful in distinguishing affected from unaffected individuals, and in studies of the pathomechanics of carpal tunnel syndrome

    Material reutilization cycles across industries and production lines

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    The concept of Industrial Symbiosis aims at organizing industrial activity like a living ecosystem where the by-product outputs of one process are used as valuable raw material input for another process. A significant method for the systematic planning of Industrial Symbiosis is found in input–output matching, which is aimed at collecting material input and output data from companies, and using the results to establish links across industries. The collection and classification of data is crucial to the development of synergies in Industrial Symbiosis. Public and private institutions involved in the planning and development of Industrial Symbiosis rely however on manual interpretation of information in the course of creating synergies. Yet, the evaluation and analysis of these data sources on Industrial Symbiosis topics is a tall order. Within this chapter a method is presented which describes value creation activities according to the Value Creation Module (VCM). They are assessed before they are integrated in Value Creation Networks (VCNs), where alternative uses for by-products are proposed by means of iterative input-output matching of selected value creation factors

    Student Employment: Linking College and the Workplace

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    The focus of National Student Employment Association (formerly the National Association of Student Employment Administrators, or NASEA) publications has always been on students in transition. From the freshman moving from high school to higher education, to the senior attempting the transition to professional employment and financial independence, we always have explored how students can better accomplish these linking experiences. Student employment is a hybrid, serving as a bridge between work and school, and ultimately, a link between school and full-time work. Student employment links elements of financial aid, career development, academic learning, experiential education, and personal development. Student employment, in all of these ways, is a bridge, moving the student from point A to point B. Because of this variety, any publication on student employment must necessarily speak to diverse themes. We have organized this publication in four sections: an introduction followed by three themed sections.https://digitalcommons.brockport.edu/bookshelf/1000/thumbnail.jp

    Mapping the prion protein distribution in marsupials: insights from comparing opossum with mouse CNS

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    The cellular form of the prion protein (PrP(C)) is a sialoglycoprotein widely expressed in the central nervous system (CNS) of mammalian species during neurodevelopment and in adulthood. The location of the protein in the CNS may play a role in the susceptibility of a species to fatal prion diseases, which are also known as the transmissible spongiform encephalopathies (TSEs). To date, little is known about PrP(C) distribution in marsupial mammals, for which no naturally occurring prion diseases have been reported. To extend our understanding of varying PrP(C) expression profiles in different mammals we carried out a detailed expression analysis of PrP(C) distribution along the neurodevelopment of the metatherian South American short-tailed opossum (Monodelphis domestica). We detected lower levels of PrP(C) in white matter fiber bundles of opossum CNS compared to mouse CNS. This result is consistent with a possible role for PrP(C) in the distinct neurodevelopment and neurocircuitry found in marsupials compared to other mammalian species

    Experimental Oral Transmission of Chronic Wasting Disease to Reindeer (Rangifer tarandus tarandus)

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    Chronic wasting disease (CWD), a transmissible spongiform encephalopathy of cervids, remains prevalent in North American elk, white-tailed deer and mule deer. A natural case of CWD in reindeer (Rangifer tarandus tarandus) has not been reported despite potential habitat overlap with CWD-infected deer or elk herds. This study investigates the experimental transmission of CWD from elk or white-tailed deer to reindeer by the oral route of inoculation. Ante-mortem testing of the three reindeer exposed to CWD from white-tailed deer identified the accumulation of pathological PrP (PrPCWD) in the recto-anal mucosa associated lymphoid tissue (RAMALT) of two reindeer at 13.4 months post-inoculation. Terminal CWD occurred in the two RAMALT-positive reindeer at 18.5 and 20 months post-inoculation while one other reindeer in the white-tailed deer CWD inoculum group and none of the 3 reindeer exposed to elk CWD developed disease. Tissue distribution analysis of PrPCWD in CWD-affected reindeer revealed widespread deposition in central and peripheral nervous systems, lymphoreticular tissues, the gastrointestinal tract, neuroendocrine tissues and cardiac muscle. Analysis of prion protein gene (PRNP) sequences in the 6 reindeer identified polymorphisms at residues 2 (V/M), 129 (G/S), 138 (S/N) and 169 (V/M). These findings demonstrate that (i) a sub-population of reindeer are susceptible to CWD by oral inoculation implicating the potential for transmission to other Rangifer species, and (ii) certain reindeer PRNP polymorphisms may be protective against CWD infection

    Priorities for synthesis research in ecology and environmental science

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    ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD
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